| calc | calculation |
| CDFG | California Department of Fish and Game |
| CDF | California Department of Forestry |
| CDMG | California Division of Mines and Geology |
| CPUC | California Public Utilities Commission |
| CRWQCB | California Regional Water Quality Control Board |
| cal | calorie |
| CRT | cathode-ray tube |
| CSAT | caustic spray additive tank |
| C | Celsius |
| centerline |
| cm | centimeter(s) |
| cm/sec | centimeters per second |
| CCRWQCB | Central Coast Regional Water Quality Control Board |
| CCP | centrifugal charging pump |
| C of C | Certificate of Compliance |
| CMTR | Certified Material Test Report |
| CTE | change, test, or experiment |
| changeout (noun or adj), change out (verb) |
| checkerplate |
| checklist |
| CVCS | chemical and volume control system |
| C&RP | chemistry and radiation protection |
| cleanup (noun or adj), clean up (verb) |
| CCTV | closed circuit television |
| closeout (noun or adj), close out (verb) |
| coastdown (noun or adj), coast down (verb) |
| CFR | Code of Federal Regulations |
| coeff | coefficient |
| cogenerate |
| cold leg |
| CLT | cold leg thinning |
| CWF | cold wall factor |
| CZP | cold zero power |
| Commission (NRC or CPUC) |
| CCS | commitment control system |
| CRGR | Committee to Review Generic Requirements (NRC) |
| CCWS | component cooling water system |
| CFW | condensate and main feedwater |
| CST | condensate storage tank |
| CFCU | containment fan cooler unit |
| CHMS | containment hydrogen monitoring system |
| CHPS | containment hydrogen purge system |
| CSAS | containment spray additive system |
| CSS | containment spray system |
| CVI | containment ventilation isolation |
| CVIS | containment ventilation isolation system |
| CRDM | control rod drive mechanism |
| CRDR | control room design review |
| CRPS | control room pressurization system |
| cooldown (noun or adj), cool down (verb) |
| CDF | core damage frequency |
| COLR | Core Operating Limits Report |
| CERP | Corporate Emergency Response Plan |
| CIRC | Corporate Incident Response Center |
| CCC | Correspondence control center |
| CBLA | cost beneficial licensing action |
| cost-benefit |
| cost-effective |
| cost-plus |
| cost-reimbursable |
| C | coulomb |
| countercurrent |
| cpm | counts per minute |
| CHF | critical heat flux |
| cross flow |
| crossbar |
| cross-check |
| cross-reference |
| cross-section (adj), cross section (noun) |
| crosstie |
| crosswind |
| cc (or cm3) | cubic centimeter |
| cfh (or ft3/hr) | cubic feet per hour |
| cfm (or ft3/min) | cubic feet per minute |
| cfs (or ft3/sec) | cubic feet per second |
| cu ft (or ft3) | cubic foot |
| cu in. (or in. 3) | cubic inch |
| cu m (or m3) | cubic meter |
| cu mm (or mm3) | cubic millimeter |
| cu yd (or yd3) | cubic yard |
| Ci | curie |
| cutoff (noun or adj), cut off (verb) |
| Hz or cps | cycles per second |
